The invention relates to a device for the manufacture or repair of a three-dimensional object. The invention further relates to a method for the manufacture or repair of a three-dimensional object as well as gas conduction devices for use in a device for the additive manufacture or repair of a three-dimensional object.
Methods and devices for the manufacture of three-dimensional objects, in particular components, are known in great variety. In particular, additive fabrication methods (so-called rapid manufacturing or rapid prototyping methods) are known in which the three-dimensional object or the component is built up layer by layer by means of additive fabrication methods based on powder beds. Primarily metal components can be manufactured, for example, by laser or electron beam melting or sintering methods. In these processes, at least one powdered component material is initially deposited layer by layer on a construction platform in the region of a buildup and joining zone of the device. Afterward, the component material is locally melted and/or sintered layer by layer by means of supplying at least one high-energy beam, such as, for example, an electron or laser beam, in the region of the build-up and joining zone. In this process, the control of the high-energy beam depends on information about the layer of each component layer being produced. After the melting and/or the sintering, the construction platform is lowered layer by layer by a predefined layer thickness. Afterward, the steps mentioned are repeated until the component has been completely fabricated. Comparable additive methods are known for the manufacture of ceramic or plastic elements.
Also known from prior art are, in particular, additive manufacturing methods for the manufacture of components of a turbomachine, such as, for example, components of an aircraft engine or a gas turbine—for example, the method or a corresponding device for the manufacture of a component of a turbomachine described in DE 10 2009 051 479 A1. In this method, a corresponding component is manufactured by deposition of at least one powdered component material layer by layer on a construction platform in the region of a buildup and joining zone as well as local melting or sintering of the component material layer by layer by means of energy supplied in the region of the buildup and joining zone. The supply of energy occurs in this process via laser beams, such as, for example, CO2 lasers, Nd:YAG lasers, Yb fiber lasers, as well as diode lasers, or by electron beams.
The removal of process by-products is usually implemented in the generic devices and methods by a flow of protective gas, which is generally passed over the mentioned component platform or a buildup and joining zone. In this process, known devices for the additive fabrication of three-dimensional objects comprise a plurality of inlet nozzles for the protective gas as well as at least one suction outlet nozzle. Used, in particular, are inlet and outlet nozzles that are arranged laterally in an opposite-lying manner above the buildup and joining zone in the construction chamber or process chamber. In this case, it is advantageous when the flow of protective gas is passed homogeneously above the construction platform in regard to flow direction and flow rate. However, in the construction chamber or the process chamber, there are two prominent components that influence this homogeneity. There is, on the one hand, the overflow component for collecting excess material and, on the other hand, the coating component or coater itself. These two components have a negative influence on the flow direction and flow rate of the flow of protective gas. In particular, vortexing of the flow of protective gas on the coater and a drop in the flow in the direction of the overflow tank can occur. This leads to a deficient removal of process by-products of additive fabrication methods. Thus, for example, in known devices for selective laser beam melting, an increase in flaws occurs in certain regions of the construction chamber in the process and in the component, so that these regions have to be blocked for the production of components in series. These flaws occur, in particular, on account of the mentioned deficient removal of process by-products. The process by-products in selective laser beam melting can be, in particular, smolder (welding fumes), spatter, ejected material, and dispersed powder. Smolder, in particular, leads to defocusing and shielding of the laser beam. As a result, the energy density that needs to be introduced onto the melting material drops and the powder is melted only deficiently. This leads to deficient bonding to the component, as a result of which, in turn, bonding flaws can occur in the component. In addition, spatter and ejected material lead to a marked local increase in the layer thickness. As a result, deficient bonding to the component and bonding flaws, in turn, can occur.